The present invention relates to a taping knife and more particularly to a taping knife having an ergonomically shaped handle formed of lightweight, yet strong, interlocking component parts. Furthermore, this invention accepts a hammer head that can be molded in place without the need for a fastener.
Taping knives, which have varying blade widths, are used to finish drywall construction projects and create a smooth transition between abutting drywall surfaces. After drywall boards are in place, a smaller (e.g. 4-6 inch) taping knife is generally used to apply a drywalling compound (often referred to as "mud") and drywall tape to the joints formed by the abutting drywall surfaces. At this stage, unseated nails must also be finally set into the boards. After the mud dries, progressively larger (e.g. 8 inch-14 inch) knives are used to apply more mud to the joint areas. This step is repeated until the joint is sufficiently flat and smooth.
A firm grip upon the handle of a taping knife is advantageous to prevent the knife from turning or slipping when smoothing mud or when its handle end is being used to sink nails. Present taping knives often use plastics, such as glass-filled nylons, polyolefins, or wood, for the handle. However, the low coefficient of friction on the smooth outer surface of the handle allows slippage of the trowel in the user's hand, particularly where the hand becomes wetted from perspiration or mud.
When taping knives are used to spread mud, the user tends to grasp the body of the handle with three to five fingers. The index and middle fingers are often extended forward, towards or resting on the blade, for added control of the angle and pressure of the blade's working face as presented to the work surface. The user's fingers and palm are prone to become chapped and may develop callouses wherever slippage or chafing occurs between the handle and the hand. A major factor promoting callousing of the hand is the presence of mud. Mud serves as an irritant by its abrasiveness as well as its chemical effect on the skin.
Present taping knives often use injection moldable plastics, such as glass-filled nylons or polyolefins, for the handle. However, when hollow plastic handles are used, watertight seals must be maintained around the joints in the component plastic parts because the complete tool is often submerged in water for cleaning. If water leaks into the handle's hollow cavities, then the weight advantage of a hollow structure may be reduced significantly. Often the manufacturing and final assembly processes, to achieve the necessary tolerances for proper handle assembly with watertight seals, become complex and expensive.